This section provides background information related to the present disclosure which is not necessarily prior art.
Tonneau covers have been used for a number of years to cover the cargo box of pickup trucks against dirt, debris, and other environmental contaminants and to improve the aesthetic quality thereof. Tonneau covers can include a flexible cover of fabric, flexible plastic, or other flexible sheet material, such as canvas, vinyl plastic or other weather-resistant fabric. When deployed, the flexible cover is commonly secured between headers and to side rails forming a metal frame around the edge of the cargo bed. Because pickup trucks generally are used and stored outdoors, the fabric cover and the metal frame are exposed to the moisture, extreme heat and cold, dust, mud, rocks and other environmental conditions and material. Mechanisms have been developed to provide proper tensioning of the flexible sheet material to prevent flapping, sagging and other disadvantages. Nevertheless, there remains a need for such tensioning mechanisms with improved functional, cost, and/or use characteristics.